HEALON® HEALON® GV
Pharmacia & Upjohn
Description: Sodium hyaluronate is a sterile, nonpyrogenic, viscoelastic preparation of a highly purified, noninflammatory, high molecular weight fraction of sodium hyaluronate. Healon contains 10 mg/mL of sodium hyaluronate 5 000 and Healon GV contains 14 mg/mL of sodium hyaluronate 7 000 dissolved in physiological sodium chloride-phosphate buffer (pH 7.0 to 7.5). This high molecular weight polymer is made up of repeating disaccharide units of N-acetylglucosamine and sodium glucuronate linked by b 1-3 and b 1-4 glycosidic bonds.
Sodium hyaluronate is a physiological substance that is widely distributed in the extracellular matrix of connective tissues in both animals and man. For example, it is present in the vitreous and aqueous humor of the eye, the synovial fluid, the skin and the umbilical cord. Sodium hyaluronates prepared from various human and animal tissues are not chemically different from each other.
Healon is a specific fraction of sodium hyaluronate developed as an ophthalmosurgical aid for use in surgery. It is specific in that: it has a high molecular weight; it is reported to be nonantigenic; it does not cause inflammatory or foreign body reactions; it has a high viscosity; it is transparent.
Healon GV contains a specific high molecular weight fraction of sodium hyaluronate developed as an ophthalmosurgical aid for use in anterior segment procedures. Healon GV is specific in that it has a high viscosity, it is highly elastic and it does not cause inflammatory or foreign body reactions.
Sodium hyaluronate protects corneal endothelial cells and other ocular structures. It does not interfere with epithelialization and normal wound healing.
Indications And Clinical Uses: The principle intended use for Healon is as an ophthalmosurgical aid in various anterior segment procedures, such as intra- and extra capsular cataract surgery, intraocular lens (IOL) implantation, keratoplasty, glaucoma surgery and post-trauma surgery. It has also been used successfully as a vitreous replacement after vitrectomy and retinal detachment surgery.
Healon GV is indicated for use as a surgical aid in various anterior segment procedures, such as cataract extraction, (IOL) implantation, corneal transplant surgery, glaucoma filtration and trauma surgery.
In surgical procedures in the anterior segment of the eye, instillation of sodium hyaluronate serves to maintain a deep anterior chamber during surgery, allowing for more efficient manipulation with less trauma to the corneal endothelium and other surrounding tissues.
Due to its viscoelasticity, Healon and Healon GV can be used to manoeuvre and control tissues.
Contra-Indications: At present, there are no known contraindications to the use of Healon and Healon GV when used as recommended.
Precautions: Those normally associated with the surgical procedure being performed should be observed.
Overfilling of the anterior or posterior segment of the eye with Healon and Healon GV may cause increased intraocular pressure.
Postoperative intraocular pressure may be elevated as a result of pre-existing glaucoma, compromised outflow and by operative procedures and sequelae thereto, including enzymatic zonulysis, absence of an iridectomy, trauma to filtration structures, and by blood and lenticular remnants in the anterior chamber. Since the exact role of these factors is difficult to predict in any individual case, the following precautions are recommended:
1. Do not overfill the eye with sodium hyaluronate (except in glaucoma surgery, see Dosage).
2. Remove some of the sodium hyaluronate by irrigation and/or aspiration at the close of surgery (except in glaucoma surgery, see Dosage).
3. Carefully monitor intraocular pressure, especially during the immediate postoperative period. If significant rises are observed, treat with appropriate therapy.
When air is used in conjunction with sodium hyaluronate, care should be taken to avoid trapping the air behind the iris.
Because sodium hyaluronate is a highly purified fraction extracted from avian tissues and is known to contain minute amounts of protein, the physician should be aware of potential risks of the type that can occur with the injection of any biological material.
Physicians should be aware that the solution may contain minute rubber particles presumably formed when the diaphragm is punctured. Express a small amount of sodium hyaluronate from the syringe prior to use, and carefully examine the solution as it is injected.
Sporadic reports have shown that Healon may become cloudy or form a slight precipitate following instillation into the eye. The clinical significance of the precipitate, if any, is not known since no effect on ocular tissues has been identified. Physicians should be aware of this phenomenon and, should it be observed, the cloudy or precipitated material should be removed by irrigation and/or aspiration. In vitro laboratory studies have shown opalescence of sodium hyaluronate when mixed with solutions containing quarternary ammonium compounds. Therefore, sodium hyaluronate should not be instilled through a cannula used in connection with such solutions. Consequently, reuse of cannulas should be avoided.
Use only if solution is clear.
Adverse Reactions: Healon and Healon GV have been extremely well tolerated after injection into human eyes. A transient rise of intraocular pressure postoperatively has been reported in some cases.
Rarely, postoperative, inflammatory reactions (iritis, hypopyon) following the use of sodium hyaluronate, as well as incidents of corneal edema and corneal decompensation have been reported. Their relationship to sodium hyaluronate has not been established.
Dosage And Administration: Cataract Surgery, I0L Implantation: A sufficient amount of sodium hyaluronate is slowly and carefully introduced into the anterior chamber to replace the aqueous humor before any instrument is introduced into the eye. Filling the anterior chamber and the capsular bag facilitates in-the-bag implantation.
Additional sodium hyaluronate can be injected during surgery to replace any sodium hyaluronate lost during surgical manipulation (see Precautions).
Glaucoma Filtration Surgery: In trabeculectomy, sodium hyaluronate is injected slowly and carefully through a corneal paracentesis to reconstitute the anterior chamber. Further injection can be continued to allow it to extrude into the subconjunctival filtration site through and around the sutured outer scleral flap.
Corneal Transplant Surgery: During trepanation of the cornea, the anterior chamber is filled with sodium hyaluronate. The donor graft can then be placed on top of the bed of sodium hyaluronate and sutured in place. Additional Healon may be injected to replace any Healon lost as a result of surgical manipulation (see Precautions).
Trauma: Healon GV can be used in the management of various kinds of penetrating eye trauma. It is injected to reform the anterior chamber, to manoeuvre, protect and support ocular tissues and to create space for surgical instruments during reconstructive surgery.
Availability And Storage: 10 mg: Each mL of sterile, nonpyrogenic, viscoelastic preparation contains: sodium hyaluronate 5 000, 10 mg. Nonmedicinal ingredients: disodium hydrogen phosphate dihydrate, sodium chloride, sodium dihydrogen phosphate hydrate and water for injection USP q.s. Disposable glass syringes, delivering 0.55 and 0.85 mL sodium hyaluronate dissolved in physiological sodium chloride phosphate buffer (pH: 7.0 to 7.5).
14 mg: Each mL of sterile, nonpyrogenic, viscoelastic preparation contains: sodium hyaluronate 7 000, 14 mg. Nonmedicinal ingredients: disodium hydrogen phosphate dihydrate, sodium chloride, sodium dihydrogen phosphate hydrate and water for injection USP q.s. Disposable glass syringes, delivering 0.55 and 0.85 mL sodium hyaluronate dissolved in physiological sodium chloride phosphate buffer (pH: 7.0 to 7.5).
A sterile single-use 27G eye cannula is supplied in the box. Syringes are terminally sterilized and aseptically packaged. Prior to use, ensure that the assembled unit functions properly by expressing a small amount of Healon or Healon GV from the syringe. Inspect the expressed solution. Do not use if the solution is cloudy or if rubber particles are present. Refrigerated Healon and Healon GV should be allowed to attain room temperature (approximately 30 minutes) prior to use. Store at 2 to 8°C. Protect from freezing. Protect from light.
HEALON® HEALON® GV Pharmacia & Upjohn Sodium Hyaluronate Ophthalmosurgical Aid
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